Photos of Comet ISON

Solar system imager Pete Lawrence of Selsey, England, took these images of Comet ISON (C/2012 S1) while in La Palma, one of Spain's Canary Islands. They show a significant difference in the comet's appearance between November 22 (left) and November 23 (right). All details are on the images.

Astroimager Gerald Rhemann of Vienna, Austria, captured Comet ISON (C/2012 S1) on November 21 at 2h49m UT from Farm Tivoli, Namibia. He imaged through a 12-inch Astro Systeme Austria ASA 12N astrograph at f/3.8. He used an FLI ML-8300 CCD camera and created an LRGB image with exposures of 3, 2, 2, and 2 minutes, respectively.

Astroimager Gerald Rhemann of Vienna, Austria, took this photograph of Comet ISON (C/2012 S1 ISON) on November 17, 2013, from Ebenwaldhöhe, Lower Austria. He used an 8-inch f/3.6 astrograph and a CCD camera. He created an LRGB image by taking exposures of 10, 3, 3, and 3 minutes, respectively, through each filter.

Solar system imager Damian Peach caught Comet ISON (C/2012 S1) at its best so far in this image made November 15 with a 4-inch Takahashi FSQ-106 refractor at f/5. He attached an SBIG STL-11000 CCD camera and took five 2-minute exposures through a luminance filter and single 2-minute exposures through red, green, and blue filters. The field of view is 2.5° wide.

Photographer Harlan Thomas of Calgary, Alberta, Canada, attached his Canon 60Da DSLR to a SkyWatcher 120ED refractor to capture Comet ISON (C/2012 S1) on November 14. He set the ISO to 2000 and took eight 5-minute exposures, which he then stacked.

Astroimager Gerald Rhemann of Vienna, Austria, took this photo of Comet ISON (C/2012) on November 12, 2013, showing that the object's tail is beginning to develop some structure. He used an 8-inch f/3.6 astrograph and a CCD camera. He created an LRGB image by taking exposures of 6, 4, 4, and 4 minutes, respectively, through each filter.

Comet ISON continues to brighten. In this image, it appears in the southeastern part of the constellation Leo the Lion. Look carefully around the field and you’ll spot several faint galaxies, including one at the very tip of the comet’s tail. Gerald Rhemann captured this image October 29 from Eichgraben, Austria, using a 12-inch Astro Systeme Austria ASA-12 astrograph at f/3.6, FLI ML-8300 CCD camera, LRGB image with 15-minute exposures through each filter.

Astroimager Damian Peach from Hampshire, England, captured Comet ISON (C/2012 S1) on October 27 through a 17-inch PlaneWave Corrected Dall-Kirkham reflector. He attached an FLI PL-6303E CCD camera and took eight 2-minute luminance images, which he combined with single 2-minute images through red, green, and blue filters. He noted the Last Quarter Moon was present.

Astroimager John Chumack from Dayton, Ohio, took this image of Comet ISON (C/2012 S1) on October 18, while it was near reddish Mars and blue-white Regulus (Alpha Leonis). He used a Canon Rebel XSi DSLR and a 170mm lens at f/6.3. He set the camera's speed to ISO 400, placed it on a tracking mount, and, at 6:27 a.m., started a 366-second exposure. He reported, "ISON had cleared the trees around 6 a.m., but dawn started to flood the image with light, not to mention the city lights over D.C. and strong light from a nearly Full Moon. Although the image is a bit noisy, it was the best one for that session."

Comet ISON (C/2012 S1) continues to move. As it does, it passes other noteworthy celestial objects. Here, Regulus (Alpha Leonis), Mars, and the comet line up. Photographer Chris Schur reported, “What a spectacular sight in my 11x80 binoculars! While the comet was quite faint, a short ¼° tail could be seen, along with the gorgeous blue and orange colors of the star and planet.” Schur captured the image October 14, 2013, from Payson, Arizona, using a 3.2-inch Zeiss apochromatic refractor at f/4.8, a Canon XTi DSLR, an ISO setting of 800, and 10 minutes of exposure.

Although it’s still invisible to the naked eye, Comet ISON (C/2012 S1) is brightening as expected. Amateur telescopes can reveal its tiny head, its growing outer atmosphere that astronomers call the coma, and its lengthening tail. And, as we see here, long-exposure images also show the comet’s greenish color. Adam Block captured this image through a 32-inch Schulman Telescope and an SBIG STX-16803 CCD camera. It's an RGB image with exposures of 18, 18, and 16 minutes, respectively, taken October 8, 2013, from the University of Arizona’s Mount Lemmon SkyCenter

Astroimager Efrain Morales of Aguadilla, Puerto Rico, captured Comet ISON (C/2012 S1) on October 6, 2013, between 8h51m UT and 9h27m UT. He used a 12-inch Meade LX200ACF Schmidt-Cassegrain telescope at f/6.3 to which he attached an SBIG ST-402ME CCD camera and an Astronomik UR/IR filter. He then took nine 4-minute exposures and stacked them. He also included two negative images (bottom), the leftmost of which reveals two faint galaxies, PGC 1509685 and PGC 28008.

Longtime Astronomy contributor Chris Schur from Payson, Arizona, sent in this photo of Comet ISON (C/2012 S1) he took October 4, 2013. He used a 12.5-inch homebuilt Newtonian reflector at f/5, an SBIG ST-10XME CCD camera, and Astrodon color filters. The total exposure time was 75 minutes, and he aligned all images on the comet's nucleus to keep ISON sharp. The effect of that technique is trailed stars. Schur reported that the comet was faint but distinctly visible through 8x50 binoculars.

Comet ISON (C/2012 S1) continues to brighten, and images of it are starting to roll in. Here’s what this longtime astrophotographer added to his submission: “The comet is very low in our eastern sky, so low in fact that the wall of the observatory has prevented me from getting a clear shot for over a month. Yesterday morning, I was able to obtain this deep image with the reflector. Everything went right: perfect focus, smooth tracking on the nucleus, and a great composition with a bright star.” (12.5-inch Newtonian reflector at f/5, SBIG ST-10XME CCD camera, five 5-minute exposures stacked, taken September 16, 2013)

Comet ISON has passed inside the orbit of Jupiter on its way to a spectacular appearance in our sky beginning this fall. On March 2, it glowed weakly at magnitude 15.3 in the constellation Gemini the Twins. Astroimager Pat Knoll created this image by combining shots at the beginning and end of a session through the 22-inch William Kuhn Telescope at the Orange County Astronomers Observatory near the town of Anza, California. The times when he captured the exposures are on the image.